A shavings-type transformer cooling system

Abstract

The shoveling type transformer cooling system comprises a closed circulation loop formed by a transformer oil tank, a first oil collecting pipe, a second oil collecting pipe and a heat sink; the heat sink is packaged by two identical aluminum alloy metal plates, a closed cavity is formed between the two aluminum alloy metal plates, a plurality of welding seams are distributed on the heat sink and divide the closed cavity into a plurality of oil channels, a plurality of same growth type fins are processed on the outer surface of the oil channels, an oil inlet is arranged at the upper end of the heat sink and is communicated with the oil distribution port and the oil channel, and an oil outlet is arranged at the lower end of the heat sink and is communicated with the oil collecting port and the oil channel. The shoveling type transformer cooling system has the advantages that when the heat generation power of the main transformer is constant, the air side convection area of the cooling device is significantly improved, the heat dissipation capacity of the cooling device is significantly increased, the heat inside the main transformer can be discharged to the surrounding environment in time, the hot spot temperature inside the main transformer is reduced, and the safe and stable operation of the main transformer is ensured.

Description

Technical Field

[0001] This invention relates to a cooling system, and more particularly to a transformer cooling device. Background Technology

[0002] The main transformer is a crucial component of a substation, playing a vital role in regulating grid voltage and ensuring the stable operation of power facilities. When operating under high loads (such as during winter heating and summer cooling), the main transformer generates significant energy losses, causing temperatures to rise in components such as the core and windings. To ensure the safe operation of the transformer, measures must be taken to dissipate the heat from the transformer body in a timely manner.

[0003] Currently, the vast majority of transformers in my country are oil-immersed transformers. In an oil-immersed transformer, the transformer core and windings, along with other heat-generating components, are submerged in insulating oil. External heat sinks are installed on the transformer's exterior. The heat generated during transformer operation causes the insulating oil to circulate within the transformer body and the heat sinks, transferring internal heat to the surrounding environment. Currently, indoor substations often use natural oil-forced air circulation cooling to reduce hot spot temperatures under high ambient temperatures and heavy loads in summer. However, because the flow of the insulating oil inside the transformer relies on the oil absorbing heat generated by the transformer core and windings, and undergoing natural circulation under gravity and buoyancy, the oil flow velocity is low, the convective heat transfer coefficient is low, and optimizing heat exchange is costly.

[0004] However, in the existing technology, the heat dissipation capacity of the transformer cooling system is limited. When the ambient temperature is high and the transformer load is large, it is difficult to ensure that the heat inside the transformer is dissipated to the outside of the main transformer in a timely manner. Due to the low heat dissipation efficiency of the transformer at present, it is difficult to ensure that the hot spot temperature of the main transformer is below the safe temperature, which may lead to a shortened service life of the transformer or even accidents such as fire. Summary of the Invention

[0005] The purpose of this invention is to provide a shovel-type transformer cooling system with high heat dissipation efficiency, which can ensure the safe and stable operation of the main transformer under high temperature environment and high load conditions.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: It includes a transformer oil tank and transformer windings and a core disposed therein. The transformer oil tank is filled with insulating oil capable of submerging the transformer windings and core. Several insulating oil outlets are provided at the upper end of the transformer oil tank wall, and several insulating oil inlets corresponding to the number of insulating oil outlets are provided at the lower end. The insulating oil inlets and outlets are respectively connected to a second oil collecting pipe and a first oil collecting pipe. Several oil distribution ports and oil collection ports are provided on the pipe walls opposite to the first and second oil collecting pipes. Several heat sinks connected to the oil distribution ports and oil collection ports are installed between the first and second oil collecting pipes. The transformer oil tank, the first oil collecting pipe, the second oil collecting pipe, and the heat sinks form a closed loop.

[0007] The heat sink is encapsulated from two identical aluminum alloy metal plates, forming a closed cavity between the two plates. Several weld lines are distributed on the heat sink to divide the closed cavity into several oil channels. Several identical growth-type fins are processed on the outer surface of the oil channels. An oil inlet connected to the oil distribution port and oil channels is provided at the upper end of the heat sink, and an oil outlet connected to the oil collection port and oil channels is provided at the lower end.

[0008] The thickness F of the aluminum alloy metal plate p It is 1-2mm.

[0009] The grown fins are machined by using a cutting tool to scrape the outer surface of the oil passages. The thickness F of the grown fins is... t It is 0.2-0.3mm.

[0010] The angle formed by the line connecting the top and root of the growing fin and the plane of the heat sink is the tilt angle θ of the growing fin, which is 75°-85°.

[0011] The installation spacing between the heat sinks is H. r The oil passage height is H t The width of the top of the oil passage is W t The method for calculating the number n of fins grown on the outer surface of the oil duct is as follows:

[0012] The oil distribution port and oil collection port are equally spaced on the second and first oil distribution pipes.

[0013] The shovel-type transformer cooling system of the present invention significantly increases the air-side convection area of ​​the cooling device when the main transformer's heat output is constant, thereby significantly increasing the heat dissipation capacity of the cooling device. It can promptly dissipate the heat inside the main transformer to the surrounding environment, thereby reducing the hot spot temperature inside the main transformer and ensuring the safe and stable operation of the main transformer. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0015] Figure 2 This is a schematic diagram of the structure of the heat sink of this invention.

[0016] Figure 3 This is a schematic diagram showing the dimensions of the heat sink of the present invention.

[0017] Figure 4 (a) is a temperature field cloud diagram of a traditional plate-type radiator;

[0018] Figure 4 (b) is a temperature field distribution cloud map of the plate heat sink of the present invention.

[0019] In the diagram, 1. Transformer winding and core, 2. Transformer oil tank, 21. Insulating oil outlet, 22. Insulating oil inlet, 3. Insulating oil, 4. First oil collection pipe, 41. Oil distribution port, 5. Heat sink, 51. Oil inlet, 52. Weld bead, 53. Grown fins, 54. Oil channel, 55. Oil outlet, 6. Second oil collection pipe, 61. Oil collection port. Detailed Implementation

[0020] In order to make the technical means, improved features, and achieved objectives of this invention easier to understand, the invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without any inventive effort are within the protection scope of this invention.

[0021] See Figure 1 The transformer cooling device 00 of the present invention includes a transformer oil tank 2 and a transformer winding and core 1 disposed therein. The transformer oil tank 2 is filled with insulating oil 3 that can immerse the transformer winding and core 1. Several insulating oil outlets 21 are opened at the upper end of the wall of the transformer oil tank 2, and several insulating oil inlets 22 corresponding to the number of insulating oil outlets 21 are opened at the lower end. The insulating oil inlets 22 and the insulating oil outlets 21 are respectively connected to the second oil collection pipe 6 and the first oil collection pipe 4. Several oil distribution ports 41 and oil collection ports 61 are equally spaced on the pipe walls opposite to the first oil collection pipe 4 and the second oil collection pipe 6. Several heat sinks (5) connected to the oil distribution ports 41 and the oil collection ports 61 are installed between the first oil collection pipe 4 and the second oil collection pipe 6. The transformer oil tank 2, the first oil collection pipe 4, the second oil collection pipe 6 and the heat sinks 5 form a closed loop.

[0022] See Figure 2The heat sink 5 of the present invention is encapsulated from two identical aluminum alloy metal plates, with a closed cavity formed between the two aluminum alloy metal plates. A number of weld lines 52 are distributed on the heat sink 5 to divide the closed cavity into a number of oil channels 54. A number of identical growth-type fins 53 are processed on the outer surface of the oil channels 54. An oil inlet 51 connected to the oil distribution port 41 and the oil channel 54 is provided at the upper end of the heat sink, and an oil outlet 55 connected to the oil collection port 61 and the oil channel 54 is provided at the lower end.

[0023] See Figure 3 The thickness F of the aluminum alloy metal plate of the present invention p The thickness F of the grown fin 53 is 1-2mm. It is machined by using a cutting tool to scrape the outer surface of the oil passage 54. t The diameter is 0.2-0.3 mm. The angle formed by the line connecting the top and root of the growing fin 53 and the plane of the heat sink 5 is the tilt angle θ of the growing fin, which is 75°-85°.

[0024] The installation spacing between heat sinks 5 is H r The oil passage height is H t The width of the top of the oil passage is W t The method for calculating the number n of fins that can be machined on the outer surface of the oil passage is as follows:

[0025]

[0026] Where n is an integer, and [X] represents taking the integer part of the real number X.

[0027] The width W at the top of the oil passage t At a given time, the more growth-type fins are processed, the greater the spacing P between the growth-type fins. f The smaller the value, the shorter the length of the growing fins. Based on different geometric parameter models, the spacing P of the growing fins is obtained through numerical simulation. f Based on the relationship between the performance of transformer cooling devices and the number of fins that can be machined on the outer surface of the oil passages, the plate-type radiator has better heat dissipation capacity when the following formula is satisfied:

[0028]

[0029] Where n is an integer, and [X] represents taking the integer part of the real number X.

[0030] When the main transformer 00 is operating, losses occur in the transformer windings and core 1 when current flows through them. These losses are ultimately converted into heat, heating the insulating oil 3 around the transformer windings and core 1. Due to thermal expansion and contraction, the heated insulating oil 3 experiences a temperature increase and a decrease in density. Under the influence of gravity and buoyancy, the high-temperature insulating oil 3 flows upward. The high-temperature insulating oil 3, with a certain flow velocity, is distributed through the first oil collecting pipe 4 to each heat sink 5. Through the heat sink 5, it exchanges heat with the surrounding air via convection. After heat exchange, the temperature of the insulating oil 3 decreases and its density increases. Under the influence of gravity, it collects in the second oil collecting pipe 6 and flows back to the main transformer tank 2. This process repeats, and the insulating oil 3 forms a circulation between the main transformer tank 2 and the heat sink 5, transferring the heat generated by the transformer windings and core 1 to the surrounding environment in a timely manner. This reduces the internal temperature of the main transformer 00 and ensures its safe and stable operation.

[0031] Although the present invention has been described in detail and illustrated with figures, it will be understood by those skilled in the art that variations, optimizations and improvements can be made to the embodiments of the present invention without departing from the principles of the invention. However, the scope of the present invention is defined by the appended claims and their equivalents.

[0032] The heat sink in this invention was numerically simulated and verified against the traditional heat sink in the background technology. To simplify the workload, the oil passage in the model was selected for numerical simulation and comparative analysis. The geometric dimension of the oil passage in the two models is 500mm in length.

[0033] Numerical simulations of two types of plate-type heat sinks were performed using STAR-CCM+ software, with identical boundary conditions and external environmental factors. Specifically, the inlet conditions were an insulating oil flow velocity of 0.05 m / s and an insulating oil temperature of 343.15 K; the external environmental heat transfer conditions were natural convection with an ambient temperature of 298.15 K; and the air-side natural convection heat transfer coefficient was set to 6 W / m². 2 K.

[0034] See Figure 4 The temperature field distribution cloud maps of the numerical simulation results are shown in the following figures (Figure (a) is the temperature field cloud map of the traditional plate-type radiator, and Figure (b) is the temperature field distribution cloud map of the plate-type radiator of the present invention):

[0035] The numerical simulation results are compared in the table below:

[0036] plate heat sink Heat dissipation (W) Outlet temperature (K) Traditional 20.09 342.18 This invention 37.47 341.35

[0037] Numerical simulation results show that, under the same inlet oil velocity and external environmental conditions, the heat dissipation performance of the heat sink of this invention is significantly better than that of traditional heat sinks. Therefore, it can also be seen that the cooling performance of the shovel-type transformer cooling system of this invention has obvious advantages.

Claims

1. A transformer cooling system, characterized by: The utility model relates to a transformer oil tank (2) and the transformer winding and iron core (1) are set in it, fill in transformer oil tank (2) with the insulating oil (3) that can immerse transformer winding and iron core (1), open a plurality of insulating oil export (21) on the wall surface of transformer oil tank (2) upper end, open a plurality of insulating oil import (22) corresponding with the number of insulating oil export (21) lower end, insulating oil import (22), insulating oil export (21) respectively with second oil collecting pipe (6), first oil collecting pipe (4) link to each other, and open a plurality of oil distribution port (41) and oil collecting port (61) on the pipe wall opposite first oil collecting pipe (4) with second oil collecting pipe (6), install a plurality of heat dissipation fin (5) with oil distribution port (41) and oil collecting port (61) link to each other between first oil collecting pipe (4) with second oil collecting pipe (6), and transformer oil tank (2), first oil collecting pipe (4), second oil collecting pipe (6) and heat dissipation fin (5) constitute a closed circulation loop; The heat dissipation fin (5) is packaged by two identical aluminum alloy metal plates, a closed cavity is formed between the two aluminum alloy metal plates, a plurality of welding beads (52) are distributed on the heat dissipation fin (5) and divide the closed cavity into a plurality of oil channels (54), a plurality of same growth type fins (53) are processed on the outer surface of the oil channels (54), an oil inlet (51) is arranged at the upper end of the heat dissipation fin and is connected with the oil distribution port (41) and the oil channel (54), and an oil outlet (55) is arranged at the lower end of the heat dissipation fin and is connected with the oil collecting port (61) and the oil channel (54); The included angle between the top end of the growth type fin (53) and the root of the growth type fin (53) and the plane of the heat dissipation fin (5) is the inclination angle θ of the growth type fin, and the inclination angle θ is 75°-85°; The mounting interval between the fins (5) is H r , the oil passage height is H t , the width of the top of the oil passage is W t , and the calculation method of the number n of the oil passage outer surface growth type fins is:

2. The transformer cooling system of claim 1, wherein: The thickness F of the aluminum alloy metal plate p It is 1-2mm.

3. The transformer cooling system of claim 1, wherein: The growth-type fin (53) is processed by shaving the outer surface of the oil passage (54) with a blade, and the thickness F of the growth-type fin (53) is 0.2-0.3 mm. t 0.2-0.3 mm.

4. The transformer cooling system of claim 1, wherein: The oil distribution port (41) and the oil collecting port (61) are equally spaced on the second and first oil collecting pipes.

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